Hypervigilance for innocuous tactile stimuli in patients with fibromyalgia: an experimental approach.

BACKGROUND: Hypervigilance, i.e., excessive attention, is often invoked as a potential explanation for the observation that many individuals with fibromyalgia show a heightened sensitivity to stimulation in various sensory modalities, such as touch and hearing. Compelling evidence for this assumption is, however, lacking. The aim of the present study was to investigate the presence of somatosensory hypervigilance in patients with fibromyalgia. METHODS: Fibromyalgia patients (n = 41) and a matched control group (n = 40) performed a tactile change detection task in which they had to detect whether there was a change between two consecutively presented patterns of tactile stimuli presented to various body locations. The task was performed under two conditions: in the unpredictable condition, tactile changes occurred equally often at all possible body locations; in the predictable condition, the majority of tactile changes occurred at one specific body location. RESULTS: It was hypothesized that the fibromyalgia group would show better tactile change detection in the unpredictable condition and when changes ocurred at unexpected locations in the predictable condition. The results did not support this hypothesis. In neither condition was the fibromyalgia group better than the control group in detecting tactile changes. CONCLUSIONS: No evidence was found to support the claim that patients with fibromyalgia display somatosensory hypervigilance. This finding challenges the idea of hypervigilance as a static feature of fibromyalgia and urges for a more dynamic view in which hypervigilance emerges in situations when bodily threat is experienced.

Fibromyalgia patients and controls are equally accurate in detecting tactile stimuli while observing another in pain: an experimental study.

This study investigated the effects of observing pain in others upon vicarious somatosensory experiences and the detection of somatosensory stimuli in both fibromyalgia (FM) patients and controls. The putative modulatory role of dispositional empathy, hypervigilance to pain, and central sensitization was examined. FM patients (n = 39) and controls (n = 38) saw videos depicting pain-related (hands being pricked) and non-pain-related scenes, while occasionally experiencing vibrotactile stimuli themselves on the left, right, or both hands. Participants reported the location at which they felt a somatosensory stimulus. Tactile and visual scenes were presented in the same spatial location (congruent; e.g., left-left) or from opposite locations (incongruent; e.g., left-right). We calculated the proportion of correct responses, vicarious somatosensory experiences (i.e., trials on which an illusory somatosensory experience was reported while observing pain-related scenes), and neglect errors (i.e., reporting only the site congruent to the visual pain-related information when both hands had been stimulated). Observing another in pain resulted in an equal numbers of vicarious somatosensory experiences in both groups and facilitated the detection of tactile stimuli, especially during spatially congruent trials. Counter to our expectations, this facilitation was not moderated by group. FM patients made fewer neglect errors. Hypervigilance for pain, dispositional empathy, and central sensitization did not exert a modulatory role. Observing pain facilitates the detection of tactile stimuli in FM patients and controls. Overall, a low incidence of vicarious experiences was observed. Further research is needed to understand the role of attentional body focus in the elicitation of vicarious experiences.

Nerve root sleeve injections in patients with failed back surgery syndrome: a comparison of three solutions.

OBJECTIVE: To evaluate outcome in patients with failed back surgery syndrome treated with nerve root sleeve injections. DESIGN AND PATIENTS: An open, nonblinded, randomized study on 60 patients with documented fibrosis in fewer than three nerve roots. INTERVENTIONS: After random selection, 20 patients were injected with 1 ml bupivacaine 0.5% combined with 1500 units hyaluronidase and 1 ml saline per nerve root sleeve (group A), another 20 were treated with 1 ml bupivacaine 0.5% combined with 40 mg methylprednisolone solution (Depo Medrol) per nerve root (group B), and a third group was treated with bupivacaine 0.5% combined with 1500 units hyaluronidase and 40 mg methylprednisolone solution (group C). The volume of each injection was 2 ml. The injections were given twice at an interval of 1 week. OUTCOME MEASURES: The patients were evaluated on a verbal pain rating scale 1, 3, and 6 months after the second injection. The Kruskal-Wallis test was used to detect statistically significant differences among the three groups, and the analysis was refined with the Friedman test. RESULTS AND CONCLUSIONS: Overall, although injections induced analgesia at 1 month, these effects were reduced at 3- and 6-month follow-ups. No statistical differences were found between the three treatment groups (after 1 month, p = 0.71; after 3 months, p = 0.69; after 6 months, p = 0.66. The Friedman test showed a significant decrease in treatment score as a function of time in groups B and C (p = 0.015) but not in group A (p = 0.074). Corticosteroids seem responsible for the last phenomenon.

[Postoperative analgesia following surgical correction of hypospadias]. / Analgésie post-opératoire après une opération de l'hypospadias.

The authors describe the different forms of postoperative pain therapy which can be applied after a surgical repair of hypospadias. Hereby we chose for the caudal analgesia. It is effective, easy to perform and is seldom associated with complications. An overview is given of the technique, the points for attention and the different products which can be injected. Systemic analgesia and penile nerve blockade are often less effective and should only be applied in case caudal analgesia can not be administered.